^ Good, you have access to what you need first and foremost. The most cost effective money you will ever spend is a one on one session with a pro. Not anyone, a pro. They are out there, you need to ask around. Some of the most effective coaching I ever had was the least expensive.
A professional coach will answer all of your questions - based on your current ability and future goals. They will set your footplate, feather and length correctly. They will watch you paddle and suggest exactly what to think of in the future. That's where the real payoff is, the coach noting your weak spots and adjusting everything to shorten the learning curve.
Paddlers also have wildly different personalities. A pro coach will listen to you and make note of your ego. That's what screws most guys from day one.
This goes directly to your point about tagging along with paddlers on a downwind run. Experienced paddlers, in general, don't want a newer paddler along, because they watch out for each other. You will eventually get on with a group, but you had better be humble and polite. You just don't know what you don't know yet about downwinding.
Overconfidence and inexperience is a dangerous combination. Give it time. Learn the basics in a stable boat, maybe get a spec ski if you want to surf waves, whatever. The pro will answer all that.
The answers most beginners get on this forum are incorrect. All too often, a new paddler's questions are seen as a launching pad for some random beginner to write about his progression in the sport. Beware of wildly differing views in surfski. That's where a one on one lesson's value comes in. All that internet noise goes away and you can think about what is tailored for you and you alone.
Big fan of reviews like this. He's very diplomatic about paddlers with "too many numbers on their boats."